1. Field of the Invention
The present invention relates to an antenna module provided in an electronic device with a wireless communication function. More particularly, the present invention relates to an antenna module which can minimize the occupying space in an electronic device and enhances a degree of freedom of the installation structure of the antenna module, increasing efficiency in space utilization in the electronic device, thereby accommodating miniaturization and multi-functionality of the electronic device, and an electronic device having the same.
2. Description of the Related Art
The recent advancement in the semiconductor and telecommunication technology has led to extensive use of electronic devices having a wireless communication function (hereinafter referred to as “wireless electronic devices”) with enhanced mobility and portability for users, and the most representative example is mobile phones. These wireless electronic devices are developed in more light-weight and miniaturized forms in order to meet the most basic needs of portability for the users.
In addition, in order to meet the needs of the users to conveniently carry a single device having multiple functions, the current trend is to add more functions including MP3, camera, credit card, wireless contact-type transportation card to the wireless electronic device.
In accordance with the current trend, there have been researches on miniaturization of components provided in the wireless electronic devices, and the antennas for sending and receiving wireless signals are not an exception to this trend.
In a conventional wireless electronic device, an internal antenna is mostly used to minimize the product size. The internal antennas include a microstrip patch antenna, a flat inverted F-type antenna, and a chip antenna.
The microstrip patch antenna takes a form of a microstrip patch printed on a printed circuit board. On the other hand, the chip antenna is made up of a plurality of layers of diverse radiation patterns including a spiral form inside a dielectric block. The plurality of radiation patterns are electrically connected to function as an antenna having a current route corresponding to a wavelength.
As shown in FIG. 1, the flat inverted F-type antenna, includes a radiation patch 11 at a predetermined height, a feeder line 12 and a ground line 13 for applying current to a corner of the radiation patch 11. The feeder line 12 and the ground line 13 are disposed perpendicular to the radiation patch 11, and bonded to feeder and ground patterns on a substrate 10, respectively.
The radiation patch 11 can basically have a rectangular shape, and here, the rectangular planar surface of the radiation patch 11 is divided by a certain shape of slits to form a spiral shape. The shape of the radiation patch 11 may take diverse forms. In the example illustrated in FIG. 1, the radiation patch 11 has two current routes, sending and receiving the frequency signals equivalent to the electrical length of the current routes. At this time, the radiation patch 11 and the feeder and ground lines 12 and 13 may be carried by, for example, a ceramic block.
However, as shown in FIG. 1, when being installed in a wireless electronic device assembly 10, the conventional internal antenna requires a certain size or larger neutral space in order to maintain its characteristics. Therefore, the conventional internal antenna takes up a space larger than its size in the wireless electronic device. However, no matter how small the space is, it is difficult to make a space for the internal antenna in the current miniaturized and multi-functioned wireless electronic devices. Conversely, saving the space will allow further miniaturization of the wireless electronic devices, and therefore, the installation space of the antenna module needs to be reduced as much as possible.
Related to the above conventional art, Japanese Laid-Open Publication Application No. 2003-87022 discloses an antenna module having high mounting density. FIG. 2 is a perspective view illustrating the antenna proposed in the application. Referring to FIG. 2, in the above-proposed antenna module, a waveguide 24 extends from a side surface of a mounting substrate 21 with a driving circuit 23 which feeds current to an antenna module 22. The waveguide 24 is used to connect the driving circuit 23 and the antenna element 22, and is formed on a flexible hard member, so that the waveguide 24 can be folded to dispose the antenna element 22 in three dimensions. The above construction of the antenna module allows integral formation of the antenna element 22, the waveguide 24, and the mounting substrate 23, reducing the assembling steps and ensuring a degree of freedom in disposing wires and components.
However, in the above-described antenna module, when the waveguide 24 is folded vertically to install the manufactured antenna module in the wireless device, the impedance of the waveguide 24 is changed, thereby weakening the antenna characteristics.
Therefore, there have been needs for researches on an antenna module which does not take up much space and has a high degree of freedom in disposition.